


The Potions Master

by Quecksilver_Eyes



Category: Harry Potter - J. K. Rowling
Genre: M/M, Regulus Black Lives, Walburga Black's A+ Parenting, also, in which Regulus has Trouble with Water
Language: English
Status: Completed
Published: 2018-07-30
Updated: 2018-07-30
Packaged: 2019-06-18 22:33:59
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,042
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15496167
Author URL: https://archiveofourown.org/users/Quecksilver_Eyes/pseuds/Quecksilver_Eyes
Summary: The worst thing about surviving the Inferi and their grasping hands are the showers. Stepping under the warm water, with nothing but his fear and his hands, feels like drowning again, like the water filling his lungs, the mark on his arm burning. (“Use a cleaning spell”, Minerva says, every day at the breakfast table, slicing her bread in two. He shrugs and reaches for the coffee. It doesn’t feel clean enough, he wants to say, and I do not know if I can trust my hands. “I don’t like them”, he says instead, and puts three spoonfuls of sugar into his cup. He can feel his mother’s disapproving frown, as if she was standing next to him, her hand cold and hard on his shoulder.)





	The Potions Master

The worst thing about surviving the Inferi and their grasping hands are the showers. Stepping under the warm water, with nothing but his fear and his hands, feels like drowning again, like the water filling his lungs, the mark on his arm burning. (“Use a cleaning spell”, Minerva says, every day at the breakfast table, slicing her bread in two. He shrugs and reaches for the coffee. _It doesn’t feel clean enough_ , he wants to say, and _I do not know if I can trust my hands._ “I don’t like them”, he says instead, and puts three spoonfuls of sugar into his cup. He can feel his mother’s disapproving frown, as if she was standing next to him, her hand cold and hard on his shoulder.)

 

* * *

 

Teaching potions is, in a way, therapeutical. The ingredients do not mind his shivering hands or the scars on his arms, and he needn’t clutch his wand to teach a gaggle of school children about bezoars and polyjuice potion. (They ask him questions, too, about things other than potions, about the look in his eyes and the scars on his skin and the faded aching mark on his forearm. He shrugs and continues willing the chalk across the chalkboard.) The year Harry Potter and all the children his age start Hogwarts, is the year Regulus begins again wishing he’d gotten an answer out of Sirius when he visited him, a year after the Potters’ house was nothing but rubble and dust. “It’s my fault”, Sirius had said, and nothing more. Bellatrix, a cell or so away from them had laughed, and Regulus had left.

He knew, of course, that little Harry had inherited his father’s looks and his mother’s eyes, but to look at him and have James Potter look back at him with his wife’s eyes sets him back ten years, when Lily cussed out Severus, James’ arm slung tight around her waist, his brother’s wand sparking red. (He wonders, sometimes, who Sirius aimed at, just then.) Rubeus, who is sitting next to him, two ferrets slung over his shoulders, elbows him in the ribs. “Regulus”, he says, in his deep voice. “You don’t happen to have pictures of Lily and James lying around, do you? I asked Remus, but he hasn’t answered yet.” He promises to check, and, his fork already halfway to his lips, hesitates.  
“Why?”, he asks.  
Rubeus takes a bite out of his steak. “For little Harry. His folks told him nothing about his parents, so I want to make him a little something.”

The next time Regulus has Slytherin and Gryffindor first years in his dungeons, with wide eyes and hungry mouths, he wills himself to look at Harry, who is sitting next to a red haired, red cheeked Gryffindor boy in robes too big and too small for his tall gangly body. “Mr Potter”, he says and Harry looks up and almost drops his wand. “Put your wand away, please, you do not need it to cut the roots.” Harry nods, and puts the wand in his robes. Regulus smiles and continues flicking through the childhood photographs Kreacher sent him, along with the Black family ring. (“Master will surely need it”, he’d said, his ears perked up, his eyes big and round like tennis balls. “Kreacher hopes Master finds what he is looking for.” Regulus had kissed the elf’s cheek and thanked him. The pictures he put in his pockets, the ring in one of the drawers of his desk, hexing it closed for good measure. It doesn’t belong to him, not really.)

The following school year is rather uneventful. That is, until Hermione Granger and Ronald Weasley run to the principal’s office, covered in soot and blood. Regulus only realises exactly what has happened when Albus comes to him, his arms full of exhausted and unconscious eleven year old, asking for a potion to help against the effects of Fiendfyre. Harry’s scar is red and bleeding, his hands full of blisters and Regulus tries not to think of just what could harm his scar as he makes the potion with trembling hands. (Albus confirms his suspicions, after they’ve left Harry with Madam Pomfrey and her cooing. Regulus feels like drowning again.)

 

* * *

 

The next school year brings, amongst a decidedly slimmer Harry Potter, the worst collegue Regulus has ever had the misfortune to put up with. Gilderoy Lockhart is an exceptionally beautiful man, with blonde hair that always falls just right, and a smile that has, as he has no problem informing the entire staff, won Witch Weekly’s Smile Award no less than three times. (He is not entirely sure just what the award is called and when he asks Minerva, she just scoffs.) Unfortunately, he is about as pompous as he is pretty, and Regulus finds himself wishing for Sirius’ most extravagant antics to avoid putting up with Lockhart and his self congratulatory books. (There was that time he occupied their parents’ bathroom for an unprecedented twelve hours and came out with his hair dyed in Gryffindor’s colours, or that time he came into Regulus’ room after they hadn’t spoken to one another for three weeks and draped himself on Regulus’ bed, complaining about Horace Slughorn.)

He overhears the students complain about Lockhart just about as much as the staff. (Apparently, he’d made everyone take tests on his person and the fifth and seventh years, who have to worry about O.W.L.s and N.E.W.T.s respectively, are not very amused. “At least the dude with You-Know-Who in his head actually knew what he was doing”, he overhears one Hufflepuff fifth year complaining to his group of friends, and he pretends he didn’t hear a thing when Peeves tries to denigrate them. He still hasn’t quite figured out how to deal with him.) Minerva wrinkles her nose whenever someone mentions Lockhart and Lockhart remains blissfully oblivious to just about anything happening around him.

That includes the petrifying attacks carried out on students, ghosts and Argus’ cat. “The Chamber of Secrets”, Albus says, little Colin Creevey’s camera in his hands, looking at the boy’s face, frozen in shock, “has been opened again.” Regulus feels like he might throw up. His mark itches. Poppy next to him reaches for his hand and squeezes it. He lies his head on her shoulder and thinks of his mother and her smile. _Mudbloods, my love,_ she’d sneer and look at Sirius’ bloody hands, _are not worthy of what they’ve been handed._

There is victory, he supposes, in looking at this little boy and seeing a little wizard terrified of the world he lives in, not an invading creature incapable of restraining his emotions. There is victory in unlearning his mother’s sneers and the poison in her words, but he doesn’t feel victorious. Instead, he feels sick. Little Harry Potter speaks Parsletongue and commandeers snakes, little Draco Malfoy, with his father’s skin and his mother’s cold disgust, calls his peers slurs Regulus has seen spill from his mother’s lips, and they are just twelve year old boys. Half of Hogwarts runs the other way when they see little Harry and his knobbly knees, and only the Weasley twins seem to be aware of how silly it is to be afraid of a little boy brought up by muggles. “The Heir is coming”, they shout through the corridors and link their arms with Harry’s. “Enemies of the Heir, beware!”

(Teaching brings a new perspective, he thinks as he pours himself a glass of firewhiskey and offers Minerva the bottle. She looks pale and tired. He can look at his students and understand, his blood cold, his guts curling, how young they all were when their parents and the war forced them to make life altering decisions. Sirius hadn’t even taken his N.E.W.T.s when mother had chased him out of the house, his face still pimpled and boyish, his eyes cold and full of hate. He himself hadn’t even gone to Hogwarts yet when his mother sat him down and forbade contact to his brother. He hadn’t followed that particular order, had written to Sirius in secret, and begged uncle Alphard for his owl to use. It was the first order he ever disobeyed.)

It all ends with Lockhart losing his memory, little Ginny Weasley pale and trembling and afraid in a way eleven year olds shouldn’t be, and Harry Potter and Ronald Weasley covered in grime and blood. Mr and Mrs Weasley, who Regulus only remembers from being opposite them in a fight, cradle her in their arms and reprimand her, their voices soft in a way Regulus doesn’t immediately recognize. “Never trust something if you can’t see where its brain is”, says Mr Weasley, his hands around Ginerva’s little child arms. “We told you that so many times.” Ginny only cries, her face buried in her father’s robes.

Regulus offers Harry a handkerchief. “Here”, he says softly, and tries to imitate Mr Weasley’s tone of voice. “I thought you might want to be a little cleaner.” Harry takes it and smiles.  
“Thank you, sir”, he says and Regulus bites his tongue. _I was a fool_ , he wants to say, _a hateful fool, and my brother was no better and I wish you still had your parents._ ( _It is our fault._ )

After the victims have been unpetrified and consoled, Hermione Granger jumps into her friends’ arms and Regulus breathes a bit more freely. (Rubeus comes back from the freezing hell that is Azkaban and the great hall erupts in cheers. He looks pale, and thin, but he’s back, and once the students are done hugging and welcoming him, Regulus buries his head in Rubeus’s chest. Rubeus just chuckles.)

 

* * *

 

In the summer leading up to Harry Potter’s third year, Sirius escapes from Azkaban and Regulus spends most of his days in a feverish eagerness, pouring over letters and maps, and photographs. (And newspapers. There isn’t a single newspaper, magical or muggle, that doesn’t have Sirius sneering at him from its front pages, his hair a matted mess, haggard and yellow toothed. Regulus throws up into his sink and thinks of mother and her eyes.) _He escaped_ , he thinks, and, _how, how, how?_

He doesn’t think of Remus, and the rings under his eyes after every full moon, or the black hair in Sirius’ bed, thinks only of a house torn apart and corpses spilling on the concrete street as Sirius laughs and laughs and looks every inch their mother’s son.

The muggle newspapers stop reporting after nothing happens for a few weeks, after Sirius has lain eerily silent in hiding, not a soul spotting him and his waxy skin. Regulus feels sicker with every day that passes without news, and stares at his brother screaming at him from the same picture, with the same glint in his eyes, day after day. Poppy, with her strong hands, and her hair free on her shoulders, sighs when he floos her and leads him to his bed. “Sleep”, she says. “You are no use to anyone if you refuse to sleep. Look, your hands are shaking.” Regulus doesn’t say that his hands haven’t stopped shaking since he was nineteen and Kreacher dragged him out of that horrific lake, bruised and battered, his lungs filled with water. Instead, he lets Poppy tuck him in, and reaches for the bucket under his bed. ( _He’s in Hogwarts_ , Sirius had mumbled in his sleep, or so the Prophet says. Regulus tries not to think of that.)

 

* * *

 

The new school year starts with rumours and cold sadness seeping into the Great Hall. “The Dementors of Azkaban will be stationed on school grounds”, Albus says, his glasses glinting in the candle light, and Rubeus’ face grows ashen. Regulus hands him a piece of chocolate, just as the man sitting to Rubeus’ right does the same. His face is scarred and tired, his clothes old and worn. “This should help”, he says and before Regulus has time to remember where he’s seen those eyes and those hands before, Dumbledore claps his hands.

“Replacing Professor Lockhart, who had to resign last year, is Professor Lupin. He will be teaching Defence against the Dark Arts.” The students, excluding a few Gryffindors, clap only sparingly. Harry Potter looks pale and leans against his friends. Lupin. Oh dear Merlin, Regulus thinks and grasps his fork. Remus Lupin and his honey eyes. Who else.

Remus proves to be a fantastic teacher and even Regulus’ Slytherins, always suspicious of new teachers, especially those in worn Muggle clothes, seem to like him. One Slytherin girl, who comes knocking at Regulus’ door because she’d been harassed by a pair of Ravenclaw students, looks at him and smiles. “Professor Lupin is so good”, she says, her voice awed and hushed. “He told Peeves off.” Regulus nods and hums and thinks of the boy Remus was, with quick hands and a quicker tongue, Potter, Sirius and little Peter Pettigrew always by his side.

“Professor Black?” Remus smiles at him, his scars stretching across his face. “I was just looking for you.” Regulus tries not to think of the knot in his stomach.  
“You were?”  
Remus nods and closes the door behind himself. “I was doing a little introductory lesson using boggarts, since they’re usually pretty easily turned into a fun time.”  
Regulus snorts and thinks of his own boggart, the leeching dead skin and the water around him. “I’m sure”, he says and stares at the paper he’s grading. _The difference between monkshood and wolfsbane, most notably, is that there isn’t one as they are differing terms for the same plant used in-_  
“Well, apparently one of the students is very afraid of you. His boggart turned into a version of you looking like you were about to spit poison.”  
Regulus looks up. “Come again?”  
“Boggart turned into you.” Remus rubs his face. “So he tried to make it look less scary. Which apparently”, he waves his hand, “amounts to dressing you in early 19 th century clothing usually spotted on witches.” He sighs. “I’m very sorry.”  
Regulus can feel his laugh building up in his spine as Remus looks at him, the corners of his lips quirked up, his eyes gleaming. He remembers him looking at Professor Slughorn like that, after they’d stolen his supply of glacéd pineapple because, as rumour told it, he’d marvelled at Lily’s potion abilities despite her upbringing. The laugh climbs up his lungs and into his mouth when Remus’ lips start twitching and it breaks out with a snort. The knot in his stomach feels looser, and Remus grins.  
“So, why tell me? Wouldn’t it be more satisfying to watch me piece it all together?” He grins and puts down his quill.  
Remus shrugs. “I didn’t want you blaming the student. The point is to make him stop being afraid of you, not to make it worse.”  
Regulus hums and thinks of Sirius and the broom hidden under his bed. “Do you think you could give me that memory? Maybe I’ll end up liking the dress.”

Sirius breaks into Hogwarts. Twice. Harry grows more and more aggravated, and Regulus’ thoughts are a guilt filled spiral of _what have I done, what have you done, what have we done_. (He didn’t hurt anyone, thank Merlin, but he scared poor Ronald Weasley half to death, and apparently the boy’s rat is missing. He also, according to a cackling Peeves, slit open the portrait of the Fat Lady, who refuses to continue being the entrance to the Gryffindor Common Room unless given extra security, which Albus agrees to, since the painting of the knight who stood in for her for about a week was the reason Sirius got past the door. He’d had a list of passwords.) Remus grows paler and quieter each day, until Regulus can’t see the glint of mischief in his eyes anymore. He looks old, and tired.

Brewing wolf’s bane for Remus and his honey eyes is, in a way, grounding. It’s a complicated potion, and while Regulus’ shivering hands don’t ruin it, he has to concentrate and focus, lest he messes up and renders the whole thing useless. He doesn’t have time for the panicked thoughts running through his head, or the sinking feeling in his guts. Remus downs the potions for a week, once a month, and complains about its taste. “Gruesome”, he says and Regulus smiles. Remus thanks him and if Regulus passes Remus’ office more often than usually in the middle of his nightly rounds looking for students out of bed, Remus doesn’t mention it.

The last full moon before the end of the school year feels heavy and dark on all their shoulders. Rubeus spends most of it crying, and Regulus cooks tea and brews the potion over the same fire. “They’re going to kill him”, Rubeus says and blows his nose. “They’re going to kill Buckbeak and they’re going to make me watch.” Regulus says nothing and thinks of the things he’d like to tell Lucius Malfoy and his smooth voice.

Harry Potter, Hermione Granger and Ronald Weasley come knocking at Rubeus’ door then and Regulus pretends to be busy with his cauldrons as Rubeus hands the Weasley boy his rat and the children try to console him. “The executioner is coming”, he says as he looks out of the window and spots the minister, Albus and a man in dark robes heading for Rubeus’ hut. The sun hangs red and heavy over the mountains and Regulus takes the potion off the fire. “Mr Potter, Miss Granger, Mr Weasley, you should leave. And I need to be on my way as well, Professor Lupin needs his medicine.” Miss Granger looks at him, her eyebrows knitted together and he shoos them out the door and squeezes Rubeus’ hand as he passes him. Rubeus smiles through his tears.

Remus’ office is empty. The cup in Regulus’ hand is hot and heavy and the steam makes him sweat, and honey eyed Remus Lupin isn’t in his office. _Fuck_ , he thinks. _Fucking goddamn fuck._ Just as he turns around, massaging his forehead, he notices something moving out of the corner of his eyes. There’s a piece of paper lying on Remus’ table, quills and ink spilled around it. _The Whomping Willow_ , the moving point reads, and, right next to it, _Remus Lupin._ Regulus lets go of the cup and drags the map towards himself. (“We’re working on a map”, Sirius had said, when he was twelve and not yet the spitting image of what mother wanted him to be. “And it’ll show everyone on Hogwarts grounds.”) There, on the edge, moving out of the map’s range, are several names. _Harry Potter_ and _Hermione Granger_ and, a little further ahead, _Sirius Black, Ronald Weasley_ and _Peter Pettigrew._ The knot in Regulus’ guts strengthens and tightens and the scars on his arms start burning. _Oh Merlin_ , he thinks _, oh please, no._ He grabs the cup and starts running.

“Harry deserves to know why”, Remus says and his voice sounds pressed and laboured. His arms are around a man who looks faintly like Sirius, the same colour eyes, the same cheekbones, the same tattoos. The rags, the bones almost piercing through his pale skin, and the glint in his eyes look nothing like his brother, and Regulus feels like he’s drowning again.  
Sirius yanks up his arm and snarls and Regulus’ hand is around it before he even realises he’s moving. The skin is dirty and cracking and unhealthily pale, but there is no fading mark, no magic seeping into his bones. Sirius snaps his teeth at him and Regulus feels like his knees might give up from under him.  
“You asshole”, he says and feels his face set into a furious snarl. “You fucking drama queen, how hard is it to tell people that you feel guilty?” Sirius scoffs and turns around. Regulus grabs him again. “You weren’t their secret keeper, you couldn’t have been, because you don’t have a mark, you’re not a death eater, you fucking wanker!” His throat feels sore and somewhere, he can hear Remus’ voice, but there’s a bright searing heat in his skin, and he doesn’t listen. Sirius slacks in his arms.  
“Because it’s my fault. I made them change the secret keeper, and I killed them”, he says, his voice rough and ragged. Regulus can feel his lungs working, and behind Sirius, Hermione looks at him with wide eyes and a slack jaw. He lets go of his brother and picks up the cup from the floor. “Here”, he says and hands it to Remus. “You forgot to take your potion.”

They manage to force Peter Pettigrew into his human form, after Remus downed the potion, and he heads straight for the door, his eyes fleeting and small. The mark on his arm is dark, and prominent, and Regulus feels wet and bruised. Nevertheless, he holds up his wand, with shaking hands and burning rage, and before Sirius can go through with his promise to commit the murder he was imprisoned for, Harry asks them to take Pettigrew and his whimpering begging to the castle. “They’ll know you’re innocent”, he says and Sirius looks at him, slack jawed and calm for the first time since Regulus stepped into the Shrieking shack.

Pettigrew is shackled to Regulus’ and Sirius’ ankles, Regulus’ wand between his ribs. Harry and Miss Granger carry their friend and Remus leads them, his posture straight and stiff. He turns as soon as they step out of the passage, and Pettigrew between them freezes. Sirius growls. (The transformation looks painful, and Remus screams, his face distorted, his bones realigning. Regulus feels like dropping Pettigrew and casting a spell against the pain. He doesn’t. Instead, he tightens his grip around Pettigrew’s waist and watches as honey eyed Remus turns into a wolf yipping at their heels. Sirius laughs, like he did when they were children, only now his voice is deep and ragged and Regulus breathes a little lighter. Pettigrew squeaks.)

Sirius’ pardoning happens a lot faster than anyone anticipated, so when he stands in the entrance hall of Grimauldplace number 15, his hair untangled, a suitcase clutched between his fingers, Harry Potter peering curiously over his shoulder, Regulus stands knee deep in trinkets and dust. Kreacher, who has his back turned to the door, tugs at his sleeves. “Master should let Kreacher do this work”, he says and Regulus looks at him.  
“You shouldn’t do this alone, you silly elf”, he says and sighs. “But you can help me as long as you don’t overwork yourself again.” Kreacher grumbles something, grabs a pile of plates and makes his way to his parents’ bedroom.  
“I can’t believe he’s still alive”, Sirius says and looks at the walls. “What are you doing?”  
Regulus shrugs. “Spring cleaning.” He grins. “Well, actually it’s ‘Sirius-is-coming-home-so-I-finally-have-motivation-to-throw-out-everything-mother-ever-cherished cleaning’, but ‘spring cleaning’ is shorter.” He stretches and gesticulates towards the mess. “I wanted to be done by the time you came here, but I overestimated my abilities.”  
Sirius quirks a brow. “Are you doing this the muggle way?”  
Regulus nods. “Yeah, everything in here is cursed, so I’d rather not trigger anything.”  
Sirius laughs and closes the door. “Well, Harry, welcome to our home. Regulus, is my room still here?”  
Regulus nods. “Yes”, he says. “Oh, and Mr Potter, you can take your pick of the rooms, I’ll clean the one you want out so you can put your things in.” Harry Potter nods and puts down his owl.  
“I’ll help you”, he says and rolls up his sleeves. Sirius laughs and ruffles his hair. “Well, let’s get some light in here.”

 

* * *

 

The next school year is the first time since Regulus started teaching that Albus doesn’t stand up to announce a new Defence Against the Dark Arts teacher and Regulus steals a carrot from Remus’ plate. Remus laughs. (They’ve found almost all the horcruxes, Albus tells him after the feast. And if his theory is right, they’ll destroy them, too. Regulus thinks of the locket hidden behind glass and of his brother slowly getting used to the light again, and he almost doesn’t feel the mark on his arm.)


End file.
